Answer:
15.9% of babies are born with birth weight under 6.3 pounds.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 6.8 pounds
Standard Deviation, σ = 0.5
We are given that the distribution of birth weights is a bell shaped distribution that is a normal distribution.
Formula:
P(birth weight under 6.3 pounds)
P(x < 6.3)
Calculation the value from standard normal z table, we have,

15.9% of babies are born with birth weight under 6.3 pounds.
Solve for y in the first equation.
y = 4x + 6
Substitute <span>4x + 6 into the second equation.
-5x - (</span><span>4x + 6) = 21
Distribute
-5x - 4x - 6 = 21
Combine like terms
-9x = 27
Divide both sides by -9
x = -3
Substitute back into first equation
-4(-3) + y = 6
Solve for y
y = -6</span>
The probability of 1 number showing up out of 20 is 1/20
The probability of 3 different numbers showing up would be 3/20
Answer: 3/20
Answer: There are 2.25×10³⁴ bacteria at the end of 24 hours.
Step-by-step explanation:
Since we have given that
Number of bacteria initially = 1
It triples in number every 20 minutes.
So, 
So, our equation becomes

We need to find the number of bacteria that it will contain at the end of 24 hours.
So, it becomes,

Hence, there are 2.25×10³⁴ bacteria at the end of 24 hours.